The methods of rotary shadowing, freeze-etch and freeze- fracture have had significant impact on our ability to elucidate the structure of macromolecules and the architectural structures they assemble into, both in vitro and in situ. Improvements in instrumentation for these methods have substantially improved their use in the study of molecular fine structure and supramolecular assemblies of increasing complexity. At Rutgers Medical School there is a group of highly qualified investigators of matrix structure and function; of matrix molecular biology; of the relationships between matrix and cells in growth and development; and of the alterations which occur in matrix in a variety of diseases. These funded investigators are currently attempting to dissect the architecture of macromolecular complexes of matrix components by x-ray diffraction; low, intermediate and high voltage TEM; SEM; and computer assisted reconstruction of serial TEM sections. Essential for many of these studies is the use of state-of-the-art rotary shadow, freeze-etch and freeze-fracture to examine matrix structure. We request funds for the purchase of an ultra high vacuum freeze- etch unit equipped with frozen microtome, electron beam guns, quartz crystal thickness monitor from Balzers, as well as a stereoscope.